hey guys. i've been out of the dSLR game for a long time. I've been using a variety of P&S cameras for at least 5 years. Today got a T4i Rebel so I can have some dSLR fun again (back then I had a 20D and assortment of L lenses).

even though I sold my dSLR and all the gear way back then (on here), my wife insisted on keeping her film Elan 7N camera and we kept the Tamron 28-75mm f/2.8 lens we had on it then.

now the T4i came with a Canon 18-55mm 3.5-5.6 IS lens.

my instinct is to stick to using the 28-75 as I prefer that range, and I definitely prefer the f/2.8 depth of field, but as far as home photographs and low-light portraits, would the f/2.8 and better optics of the Tamron be a better idea or the IS of the Canon?

back in my day the kit 18-55mm was a pretty subpar lens. the glass on this looks subpar still, specially compared to the much bigger glass of the Tamron. but this lens is at least 4-5 years newer than the Tamron.

sorry if I gave the wrong impression in the first post. I did mention I had a 20D, which is also a 1.6x factor camera. as I said, I prefer the range of the Tamron, but that's not really the question.

my question is which would be better for low-light/in-home photographs. the Tamron with the better (?) optics and f/2.8 or the much newer but crappier glass (?) of the Canon with Image Stabilization.

EDIT: the question stems from what I hope have been leaps of improved image quality over the years. the 20D would do only ISO 3200 and it was horribly grainy. the T4i does ISO 25600 (which was unheard of at that time) and in better quality than the 20D did ISO3200. so, likewise, I wonder if the "crappy kit lens" has become better enough of the years to make it a better choice to the premium glass (for the time) of the Tamron.

The 18-55 IS kit lens is great around 5.6-8 for outside shooting and gives you a wide angle. It is much better than the old 18-55 no IS 20D kit lens. It is not worth more than $100 used so you may as well keep it and the Tamron for low light and more reach. The IS only helps with static subjects when slow shutters are the lesser of two evils (vs. ultra high ISO).

I would also say that for casual photography on a t2i,t3i,t4i and 7d you can use ISO 3200 no problem. It is a bit noisy, but in many uses this is not an issue for web and small prints (especially if you expose correctly). 6400 even works ok with some NR though it is getting much worse by then. If you are doing big prints of course you want to keep the ISO down.

Why don't you just start using your cameras and lenses and see what gaps your picture taking reveals. Then you can plug those knowing that the gear will suit both your wife's and your own style. The kit lens won't fit the 7E, but both will fit the T4i.
With your present gears you have effective focal lengths between 27mm and 112mm covered at f2.8 (45mm to 112mm) and 5.6IS (27 to 80mm). Not a bad start. Both of your lenses are said to be good (I have neither) so just pixel peep to see what satisfies your wants, remembering that 100% is a tougher test on the T4i than the old 20D.

I have a Tamron 28-75 (picked it up cheap to try) and I have to say its the worst bl..dy lens I've ever had the misfortune to mount on my camera .

My ones AF is so bad that you can forget about using it indoors . When I got it I made the mistake of only having it with me at a kids dance show in a bookshop that my daughter was in (book launch thing) . Anyway the number of infocus shots I got was nil . It's not even a front/back focus issue it just can't get a lock . It searches for a bit and then the camera says its got a lock and fires but the focus can be anywhere. My 24-105 which is a stop slower (so let's half the light in) has no trouble in the same light.
Things are better outside where at least it gets focus , but the focus is slow and noisy.

IQ is quite good when it gets focus . But I'd muc rather use something else.

If you like the range of the Tamron and want 2.8 then there are other options , but most either cost more or are not themselves great lenses .
1 option on a crop would be the sigma 17-70 . It's 2.8 at the wide end but drops to f4 . But the IQ from the newer HSM version (which is about to be replaced) is very good and it has OS

That said my vote for a crop standard zoom is the 17-55 IS . Great lens and the last 20mm can either be cropped or you footzoom

My main issue with the 18-55 is that it is not a fixed aperture. I hate shooting a lens that has to move from 3.5 to 5.6 just because I wanted a tighter shot. This changes my exposure and degrades my shot when I woyld have preferred a shallow DOF to bring out the subject. I guess if you are on full auto that may not be a problem but if you want to control the look of the shot this is a issue. I have both for my back-up camera but keep the Tamron lens on for the reasons mentioned. In the people forum you can find some amazing shots by someone using the kit lens.

I found that simply using a 430EX flash with the 18-55 IS kit lens works wonders. With a little imagination with bouncing and/or redirecting the light, it worked pretty well for me. Still no substitute for constant f/2.8.